A new £6 million helicopter has been grounded this morning for checks to be carried out.
The alarm was raised by a Yorkshire Air Ambulance pilot using the new helicopter, which took to the skies for the first time last weekend, when a warning light came on.
Helicopter manufacturer Airbus sent a mechanic to the helipad at the Northern General Hospital, where the helicopter landed earlier today.
A Yorkshire Air Ambulance spokeswoman said the checks were precautionary and it is hoped that the helicopter will be operational again later today.
"Engineers are looking at it to make sure it is safe to fly and we expect it to continue its operational duties later," she added.
A second new helicopter is on order and expected to be operational by the end of the year.
They are replacing two older helicopters and because they are able to operate in the dark they will be available to respond to emergencies for more hours every day.